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We report the spatio-temporal separation of electron and phonon thermal transports in nanostructured magnetic L10 FePt films at the nanometer length scale and the time domain of tens of picosecond, when heated with a pulsed laser. We demonstrate that lattice dynamics measured using the picosecond time-resolved laser pump/X-ray probe method on the FePt (002) and Ag (002) Bragg reflections from different layers provided the information of nanoscale thermal transport between the layers. We also describe how the electron and phonon thermal transports in nanostructured magnetic thin films were separated. [ABSTRACT FROM AUTHOR]

We report a charge-transfer mechanism in tuning of magnetism of Nd-substituted Gd5-xNdxSi4 (x=1 and 2.5) compounds. The X-ray absorption near edge structure measurements demonstrated that Nd substitutions for Gd induce charge transfer of 5d electrons from Gd to Nd. The charge transfer weakens spin-orbital coupling of Gd but strengthens that of Nd. Consequently, the magnetization responses of the substituted compounds to low magnetic fields are increased while their saturation magnetization is reduced. Electronic structure calculations showed that the charge transfer stabilizes a ferromagnetic and a ferrimagnetic structure in the compounds with x = 1 and 2.5, respectively, but that it does not change the 5d–3p hybridization significantly. It is suggested that the charge transfer of 5d electrons may occur in other rare earth-substituted Gd5Si4 compounds allowing for tuning of their magnetism. [ABSTRACT FROM AUTHOR]

Presents a study which examined the thermal stability of gallium nitride thin films grown on (001) aluminum[sub2]oxygen[sub3] and (0001)[subsilicon] 6 hydrogen-silicon carbide substrates. Experimental method; Results; Discussion.

Presents information on a study which proposed a crystallographic model to describe the epitaxial growth of wurtzite-type thin films such as gallium nitride on different orientations of sapphire substrates. Description of large-band gap semiconductors; Methodology of the study; Results and discussion.

Focuses on a study which examined thin aluminum nitride (AlN) films grown on different orientations of sapphire substrates by metalorganic chemical vapor deposition. Description of the crystal; Epitaxial relationship between AlN and gallium nitride films and sapphire substrates; Discussion on results; Interpretation of results using extended atomic distance mismatch.

Presents information on a study that examined the dynamic processes of the free transitions in GaN grown by metal-organic chemical-vapor deposition. Experimental procedure; Results and discussion on the study; Conclusions.

The grain size and grain-size distribution of sputtered L10 Fe50Pt50 (300 Å thick, composition in at. %) magnetic thin films on Cu (001) single-crystal substrate were investigated using high-resolution transmission electron microscopy sHRTEMd. The planar TEM results showed that the grain size was about 56 Å in diameter with a standard deviation of ~10%. The cross-sectioned TEM images indicated that the magnetic grains existed in columnar structures. The L10-ordered FePt films with a small grain size and narrow grain-size distribution are potential media candidates for the high-areal density magnetic recording. [ABSTRACT FROM AUTHOR]

The exchange-coupling-strength effect on the magnetic properties and noise of laminated [FeCo (t nm)/Rus0.9 nm)]nC(5 nm) films as a magnetic soft underlayer (SUL) for perpendicular recording was investigated. It is found that the remanent magnetization decreases significantly with increasing the exchange-coupling strength, whereas, the coercivity remains almost unchanged. The spike noise is clearly seen in the single layer films without exchange coupling and its peak value is as high as 250 mV. The spike noise is significantly suppressed by introducing antiferromagnetic coupling and even eliminated in the films with strongest antiferromagnetic coupling. The noise peak value can be as low as 25 mV for the films with strongest coupling. The average noise decreases with increasing exchange-coupling strength, but increases linearly with increasing the Mrt of SUL. The noise-reduction mechanism is also discussed. [ABSTRACT FROM AUTHOR]

The effect of lattice mismatch on the chemical ordering of epitaxial FePt films was studied. The results showed that the lattice constant (c) of the FePt films decreased with increasing lattice mismatch ε from about 2.23% to 6.33%. Upon further increase of ε to about 8.8%, c increased. On the other hand, the variation of the lattice constant (a) of the FePt films showed a reversal behavior to that of c with the increased lattice mismatch. The ratio c/a of the FePt films held a minimum of about 0.9466, while the chemical ordering degree and magnetic anisotropy constant held maximum values for ε around 6.33%. These results indicated that the strain from the lattice mismatch favored the ordering of the FePt films. [ABSTRACT FROM AUTHOR]

The effects of postdeposition annealing on the structural properties of CoCrPt/Ti magnetic thin films were investigated. The improvement of out-of-plane coercivity and squareness resulted from enhancement of both the crystallinity and texture of the CoCrPt (002) peak. The initial growth region of the CoCrPt layer and the Ti underlayer greatly improved in structural and magnetic properties through annealing. © 2004 American Institute of Physics. [ABSTRACT FROM AUTHOR]

The structure and interface of Co[SUB74]Cr[SUB16]Pt[SUB10] (40 nm thick)/Ti (10 nm thick) films for perpendicular magnetic recording were studied using x-ray scattering and transmission electron microscopy. Improved out-of-plane coercivity and squareness resulted from the combined effects of higher crystallinity and better texture of the CoCrPt (002) film, and increased interface roughness. The relationship of sputtering pressure to the structural effects is discussed. [ABSTRACT FROM AUTHOR]

The long-range order (LRO) and short-range order (SRO) of CoCrPt/Ti/NiP perpendicular media films were studied by synchrotron x-ray scattering and extended x-ray absorption fine structure (EXAFS) spectroscopy in order to correlate their effects with the magnetic properties. The thickness of the magnetic media films and the NiP seed layers were kept constant, whereas the Ti underlayer thickness was varied. The increase of out-of-plane coercivity and squareness was related to the increase in the crystallinity and texture of CoCrPt (002), which first increased and then decreased with increasing Ti thickness. The best magnetic properties were observed for the magnetic film grown on the 30 nm Ti underlayer. The improvement was associated with the local atomic environment in which a relatively ordered Co, and disordered Cr and Pt existed. This suggests that a higher degree of Co and Cr phase segregation contributed to the enhancement of the magnetic properties. The LRO and SRO results are consistent with the magnetic properties. [ABSTRACT FROM AUTHOR]